Objectives: To determine if adolescents with bipolar disorder (BD) perform differently from adolescents with attention deficit/hyperactivity disorder (ADHD) and healthy controls (HC) on a behavioral measure of impulsivity, the Continuous Performance Task-Identical Pairs (CPT-IP)-degraded version and a self-report measure of impulsivity, the Barratt’s Impulsiveness Scale (BIS-11) during manic and euthymic states.
Methods: Adolescents with ADHD without other co-morbidities (n=28), BD (manic/mixed) (n=33), BD (euthymic) (n=20) and HC (n=25) were administered the CPT-IP and BIS-11. We compared performance variables (perceptual sensitivity, hit reaction time (RT) and response bias) at two degradation levels (high, low) on CPT-IP and total and subscale (cognitive, motor, nonplanning) scores on BIS-11, between the groups.
Results: No significant group differences were noted in response bias and perceptual sensitivity (p>0.05). Hit RT was equal amongst groups under low degradation, but a marginally significant difference was noted between the ADHD and BD euthymic groups (ADHD group was slower than BD euthymic group) under high degradation (p=0.053). The HC group scored significantly lower than the other three groups (p<0.05) on non-planning, cognitive, and total BIS-11 scores, but on motor subscale, HC and BD euthymic groups had statistically similar scores (p=0.12).
Conclusions: It appears that when bipolar patients achieve euthymia, their motor impulsivity decreases, thereby, improving attention and processing efficiency. Although impulsivity is a prominent feature of BD and ADHD, only motor aspects of impulsivity may be useful to distinguish between them. The potential for impulsivity in BD patients appears to be high even when their mood appears to be stable.